1. Field of the Invention
The present invention relates to a recycling system for image forming apparatus such as copying machines or printers for recycling an image forming unit removably mounted in the image forming apparatus. More particularly, the invention relates to an image forming apparatus having a recyclable image forming unit removably mounted therein, and to a recycle processing apparatus for use in recycling the image forming unit.
2. Description of the Related Art
Recycling systems for image forming apparatus have been proposed heretofore to meet the demands for environmental protection and resource saving. Such an image forming apparatus includes image forming units such as a developing unit, a fixing unit and a processing unit removably mounted therein. When any of these units fails or comes to the end of its service life, the unit is removed from the image forming apparatus, renovated and sold as a recycled product.
Japanese Unexamined Patent Publication JP-A 7-66885 (1995), for example, discloses a construction for promoting recycling of image forming units. In this construction, data management is effected in relation to use periods of the respective image forming units to enable an easy determination of a time for recycling each image forming unit.
Japanese Unexamined Patent Publication JP-A 5-249830 (1993) discloses a construction including a display provided in the exterior of a toner cartridge for displaying the number of recycle times which is incremented each time the cartridge is installed in an image forming apparatus, thereby facilitating a determination to be made as to whether the cartridge may be recycled again or not.
In image forming apparatus, different control conditions such as developing bias and charge voltage during image formation take different values for maintaining an excellent image formation according to the states of image forming units such as a developing unit, a fixing unit and a processing unit. None of the conventional image forming apparatus set a control condition during image formation, based on historical data such as the numbers of recycled times of the image forming units. The control condition during image formation may not be suited to the states of the image forming units mounted in the image forming apparatus, which results in a deterioration in the quality of images formed.
For example, a processing unit including a photoreceptor not having reached the end of its service life may be recycled without changing the receptor. In the image forming apparatus having, mounted therein, the processing unit having undergone this recycle process, the control condition such as developing bias or charge voltage for achieving an excellent image formation takes a value different from an initial value, depending on the past use frequency of the photoreceptor. It is therefore necessary to vary the control condition during image formation, as appropriate, according to the use frequency of the photoreceptor included in the processing unit installed. However, none of the conventional image forming apparatus set a control condition during image formation according to the use frequency of the photoreceptor included in the processing unit installed.
When recycling each image forming unit, different processes are required according to its history such as use state of the image forming unit. None of the conventional image forming apparatus and the recycle processing apparatus are devised to classify the image forming units easily according to history. Thus, the recycle process of each image forming unit cannot be easily carried out according to its history, but consumes a long time.
Where, for example, an image forming unit includes a damaged component, the damaged component must be changed during a recycle process. None of the conventional image forming apparatus and the recycle processing apparatus are devised to notify the operator beforehand of the presence of the component needing replacement in the image forming unit to be recycled.